let num = 1;
let str = '';
let flag = true;
let un = undefined;
let obj = {};
let nu = null;
let arr = [];
let fn = function () {};
let date = new Date();

console.log(typeof num); // number
console.log(typeof str); // string
console.log(typeof flag); // boolean
console.log(typeof un); // undefined
console.log(typeof nu); // object
console.log(typeof obj); // object
console.log(typeof arr); // object
console.log(typeof fn); // function
console.log(typeof date); // object
